The equilibrium configuration, dynamics, and dissociation energy of the very weakly bonded 2,5-dihydrofuran ... Ne complex have been deduced from its free jet millimeter wave spectrum. The equilibrium distance of Ne with respect to the center of mass of the molecule is 3.30 Angstrom, with Ne tilted 7.3 degrees from the perpendicular to the center of mass of the ring toward the oxygen atom. The dissociation energy is estimated, from the centrifugal distortion constant D-J, to be ca. 1.1 kJ/mol.